The growing number of oil tankers sanctioned by the United States is limiting the availability for Iran to ship its crude as Tehran is in more intense competition with Russia and Venezuela for vessels not yet blacklisted by the U.S. Treasury. “There is only a number of tankers on the market willing to take high-risk sanctioned oil and now Iran needs to compete with Russia and Venezuela to secure them,” Muyu Xu, a senior crude oil analyst at Kpler said at an event, as carried by Bloomberg. The stricter sanctions on tankers carrying oil…